Almost every coastal city in the world depends on the Earth’s glaciers maintaining their structure. Even what sounds like small levels of sea level rise can have devastating impacts for housing, sanitation and agriculture, and lead to the displacement of millions of people. Sea level rise is one of the most serious consequences of climate change and if allowed to continue to worsen, many scientists believe will contribute to the breakdown of civilisation as we know it.
Former UK Government Chief Scientific Advisor Sir David King, during COP26, warned of some of the possible consequences of flooding by sea water, such as the collapse of rice production in regions of south east Asia. He advises that once land is flooded with seawater it is not suitable habitat for rice crops. This will in turn lead to international food trade and economy collapse as nations attempt to secure their own food supplies.
Scientists studying Antarctic ice have now discovered that the last remaining ice sheet of the Twaites Glacier, a crucial support of the structure of a larger area of the ice, is showing alarming signs of fracturing and melting, which is likely to unleash one of the many ‘tipping points’ that can escalate climate change and it’s impacts, leading to flooding of coastlines around the world over the next few decades.
The ice shelf, which is anchored on an underwater mountain, acts as a damn slowing the flow of ice from the on-land portion of the Thwaites Glacier into the ocean. In addition to the warming ocean temperature melting the ice from underneath and detaching it from its fixed grip on the mountain beneath it and thinning the ice, cracks have been observed which will cause it to break apart. Once this happens to the ice sheet, the rest of the glacier will melt into the sea.
Though the eastern ice sheet itself will not affect the sea level even if it breaks up, if the rest of the Thwaites Glacier collapses into the sea it would unleash 65cm of sea level rise, which doesn’t sound much, but is enough to cause significant coastal erosion, flooding, and human and animal displacement, as well as sanitation and food security problems.
Rather more alarmingly, the Thwaites Glacier is a key pillar of stability for the West Antarcarctic Ice Sheet. So if the Thwaites Glacier disappears into the ocean, The Western Antarctic Ice Sheet, which has the potential to add 3.3m to sea level rise, may also destabilise, causing terrible damage and suffering.
This is the reason the Thwaites Glacier is often called the ‘Doomsday Glacier’ – it’s collapse could lead ultimately to melts which would completely alter the map of the Earth. It’s not fully understood how long this process could take – it could take a couple of centuries, but it’s possible it could happen within the next few decades.
The fracturing ice shelf of the Thwaites Glacier has been variously described using analogies including the windshield of a car and chair jammed under a door handle. From the plain language summary of their assessment, scientists who detected the cracks in the ice sheet reported:
Similar to a growing crack in the windshield of a car, a slowly growing crack means the windshield is weak and a small bump to the car might cause the windshield to suddenly break apart into hundreds of panes of glass
Pettit et al, Collapse of Thwaites Eastern Ice Shelf by Intersecting Fractures
Reporter Philip Boucher-Hayes explains the scenario really well in lay-mans terms in his Twitter thread which reads:
What scientists are projecting will happen to the Thwaites Glacier in the next three to five years should be front page news everywhere today.
The Thwaites Glacier (roughly the size of Britain) is mostly held in place by a massive shelf of ice that slows its flow into the sea. That ice shelf is like a chair jammed under a door handle. But now it is beginning to slip allowing the door to open.
Warmer waters are effectively melting the ice from underneath. The shelf is getting thinner and losing its anchor on the sea bed. New analysis shows it is fracturing like a window and will in time shatter in to smaller icebergs.
This won’t cause disastrous sea level rise. The shelf displaces roughly the same amount of sea solid or liquid. It is what it is holding behind the door that matters. If the entire Thwaites Glacier slid into the ocean it would cause 65cm sea level rise. But if that happens the entire Western Antarctic sheet could also destabilise. The projected rise in that scenario is incomprehensible.
Philip Boucher-Hates (on Twitter)
There is talk among some scientists about techno-fixes such as re-freezing the poles and removing CO2 from the atmosphere with technologies that are yet to be scaled to levels required to be effective. Waiting for technology to be developed and scaled is a massive gamble. NASA Climate Scientist, Dr. Peter Kalmus, recently tweeted:
Rereading the 2018 IPCC report summary, and can’t avoid mentally replacing any mention of “carbon dioxide removal” with “magic fairy dust”. It was a huge mistake for the IPCC to present scenarios underpinned with massive amounts of speculative carbon capture technologies which do not, and may never, exist at scale. These fantasy scenarios do not belong in a scientific report. Almost no policymaker would be able to resist the temptation of such fantastically optimistic scenarios. Including them and elevating them in this was a dangerous distraction, which could have been just as easily avoided.
Peter Kalmus (on Twitter)
The science indicates that while we continue to pump climate changing emissions into the atmosphere, we will continue to see rapid warming, which will only exacerbate the ice melt, and in turn will propagate a cascade of disasters.
With the choice between risky future technology that may or may not be effectively scaled before catastrophe strikes, or a rapid phase out of fossil fuels which we know is certain to halt further warming and melting before tipping points are reached, any sensible decision would including ending the fossil fuel era as rapidly as possible to limit the damage.
For inspiration on ways you can help, check our the Peach & Bumble blog post 3 Ways to Help the Environment.
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